Currently, there is concern about the consistent increase in the number of patients undergoing maintenance hemodialysis, including patients with terminal renal insufficiency, in the field of renal disease. In addition, two main underlying diseases for the initiation of hemodialysis are chronic nephropathy, typically IgA nephropathy, and diabetic nephropathy which tends to increase remarkably due to changes in life style.
Regarding the pathology of these renal diseases, the increase of mesangial cells and an extracellular matrix is one of the examples in various glomerulonephritis including IgA nephropathy. In diabetic nephropathy, microalbuminuria is observed in its early stage, and the increase in excretion of protein in urine leads to the risk of nephritic syndrome.
At present, studies of various drugs have been earnestly promoted for developing agents for the prevention or treatment of various renal diseases (Jpn. J. Pharmacol., Vol. 75, pp. 59-64 (1997); Exp. Nephrol., Vol. 8, pp. 135-143 (2000); FASEB Journal, Vol. 14, pp. 439-447 (2000); Kidney Int., Vol 59, p 2282 (2001); Kidney Int., Vol. 55, p. 613 (1999); Kidney Int., Vol. 60, p 715 (2001); Diabetes Care, Vol. 13, p. 1114 (1990); Kidney Int., Vol. 45, p. 794 (1994)). However, in the above situation, the importance and demands have been increasing more and more, and fast development of novel agents for the prevention or treatment of various renal diseases has been greatly desired.